# Copyright European Organization for Nuclear Research (CERN) since 2012
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""
RFIO protocol
"""

import os
from os.path import dirname
from urllib.parse import urlparse

from rucio.common import exception
from rucio.common.utils import execute
from rucio.rse.protocols import protocol


class Default(protocol.RSEProtocol):
    """ Implementing access to RSEs using the RFIO protocol. """

    def connect(self, credentials):
        """
            Establishes the actual connection to the referred RSE.

            :param credentials: needed to establish a connection with the storage.

            :raises RSEAccessDenied: if no connection could be established.
        """
        extended_attributes = self.rse['protocol']['extended_attributes']
        if 'STAGE_SVCCLASS' in extended_attributes:
            os.environ['STAGE_SVCCLASS'] = extended_attributes['STAGE_SVCCLASS']

    def path2pfn(self, path):
        """
            Returns a fully qualified PFN for the file referred by path.

            :param path: The path to the file.

            :returns: Fully qualified PFN.

        """
        return ''.join([self.rse['scheme'], '://', path])

    def exists(self, path):
        """
            Checks if the requested file is known by the referred RSE.

            :param path: Physical file name

            :returns: True if the file exists, False if it doesn't

            :raises SourceNotFound: if the source file was not found on the referred storage.
        """
        cmd = f'rfstat {path}'
        status, out, err = execute(cmd)
        return status == 0

    def close(self):
        """ Closes the connection to RSE."""
        if 'STAGE_SVCCLASS' in os.environ:
            del os.environ['STAGE_SVCCLASS']

    def put(self, source, target, source_dir, transfer_timeout=None):
        """
            Allows to store files inside the referred RSE.

            :param source: path to the source file on the client file system
            :param target: path to the destination file on the storage
            :param source_dir: Path where the to be transferred files are stored in the local file system
            :param transfer_timeout: Transfer timeout (in seconds) - dummy

            :raises DestinationNotAccessible: if the destination storage was not accessible.
            :raises ServiceUnavailable: if some generic error occurred in the library.
            :raises SourceNotFound: if the source file was not found on the referred storage.
        """
        if not self.exists(dirname(target)):
            self.mkdir(dirname(target))

        cmd = f'rfcp {source} {target}'
        status, out, err = execute(cmd)
        return status == 0

    def mkdir(self, directory):
        """ Create new directory. """
        cmd = f'rfmkdir -p {directory}'
        status, out, err = execute(cmd)
        return status == 0

    def split_pfn(self, pfn):
        """
            Splits the given PFN into the parts known by the protocol. During parsing the PFN is also checked for
            validity on the given RSE with the given protocol.

            :param pfn: a fully qualified PFN

            :returns: a dict containing all known parts of the PFN for the protocol e.g. scheme, hostname, port, prefix, path, filename

            :raises RSEFileNameNotSupported: if the provided PFN doesn't match with the protocol settings
        """
        parsed = urlparse(pfn)
        ret = dict()
        ret['scheme'] = parsed.scheme
        ret['hostname'] = parsed.netloc.partition(':')[0]
        ret['port'] = int(parsed.netloc.partition(':')[2]) if parsed.netloc.partition(':')[2] != '' else 0
        ret['path'] = parsed.path

        # Protect against 'lazy' defined prefixes for RSEs in the repository
        self.rse['prefix'] = '' if self.rse['prefix'] is None else self.rse['prefix']
        if not self.rse['prefix'].startswith('/'):
            self.rse['prefix'] = '/' + self.rse['prefix']
        if not self.rse['prefix'].endswith('/'):
            self.rse['prefix'] += '/'

        if self.rse['hostname'] != ret['hostname']:
            raise exception.RSEFileNameNotSupported('Invalid hostname: provided \'%s\', expected \'%s\'' % (ret['hostname'], self.rse['hostname']))

        if not ret['path'].startswith(self.rse['prefix']):
            raise exception.RSEFileNameNotSupported('Invalid prefix: provided \'%s\', expected \'%s\'' % ('/'.join(ret['path'].split('/')[0:len(self.rse['prefix'].split('/')) - 1]),
                                                                                                          self.rse['prefix']))  # len(...)-1 due to the leading '/
        # Splitting parsed.path into prefix, path, filename
        ret['prefix'] = self.rse['prefix']
        ret['path'] = ret['path'].partition(self.rse['prefix'])[2]
        ret['name'] = ret['path'].split('/')[-1]
        ret['path'] = ret['path'].partition(ret['name'])[0]

        return ret
